This invention relates to an opaque cladding panel for incorporation in a fully-glazed facade of a building.
Many modern commercial buildings are constructed with a substantially fully-glazed facade using tinted or semi-reflecting glass. The principal component of the facade is made up of transparent vision panels which are in effect the windows of the building, and opaque cladding panels, referred to as "spandrel panels", are embodied in the facade to mask the structural elements and service conduits of the building.
GB-A-No. 1558504 discloses a composite panel for use as a facade element for cladding wall portions of buildings. The composite panel has an outer transparent glass panel and an inner opaque glass panel parallel to and spaced from the outer panel. The space between the panels is sealed and is filled with a gas other than air which has a thermal conductivity less than that of air. GB-A-No. 1353170 discloses opaque, insulating, hermetically sealed, spandrel glazing units.
DE-PS No. 1123100 describes a prefabricated panel for the outer walls of buildings with an inner insulating panel and an outer cladding panel of material impermeable to vapour. This outer cladding panel may be glass. The inner and outer panels are held together by U shaped clamps on at least the upper and lower edges of the panel.
To avoid build up of moisture in the insulating panel, with consequent loss of insulating properties, and to allow air to pass through the panel to ensure a healthy room atmosphere, the outer panel is inset from the outer panel on its upper and lower edges, an intermediate spacer element in the form of a corrugated sheet is provided between the inner and outer panels and provision is made for the entry of air between or through the clamps.
DE-A-No. 2938762 describes the use of glazing applied to an external masonry wall for heating a building. A glazing unit, preferably a double glazing unit, is mounted on the outer face of the wall one or several centimeters in front of it by, for example, a wooden frame. The horizontal sides of the frame may be provided with closable ventilation slits.
In some buildings the spandrel panels are a good colour match with the vision panels, thus presenting a completely uniform impression to the observer from the outside of the building. In other buildings the spandrel panels contrast with the vision panels, or appear to have a different shade from the vision panels, thus producing a ribbon effect along the facade when viewed externally. The panels are mounted on a framework which usually, although not necessarily, comprises metal transom and mullion members.
In use, the appearance of such spandrel panels incorporating an outer glass sheet tends to deteriorate and become patchy and non-uniform. The deterioration may result from degradation of coatings used in the spandrel product.
It is an object of the present invention to provide a solution to this problem. The present invention accordingly relates to an opaque spandrel plane of simple construction which has an interspace which is ventilated to avoid condensation of water and/or organic vapour in the interspace.